Air-compressor.



L. L. FOSTER.

AIR COMPRESSOR.

APPLICATION FILED SEPT-27, 19:1.

Patented July 16, 1918.

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AIR COMPRESSOR.

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1 272,65 1 Patented July 16, 1918.

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ZZJ OaZ'eI" L. L. FOSTER AIR COMPRESSOR.

APPLICATION FILED SEPT-27,1917.

1 ,272,65 1 Patented July 16, 1918.

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L. L. FOSTER.

AIR COMPRESSOR.

APPLICATION FILED sEPT.27. 1917.

1,272,651. Patented July 16, 1918.

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on the LEWIS L. FOSTER, OF GOVANS, MARYLAND, ASSIGNOR OF ONE-EALF TO JOHN H. RUEHMLING, OF BROOKLYN, NEW YORK.

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Specification of Letters Patent.

Patented July 16, 1918.

Application filed September 27, 1917. Serial No. 193,569.

To all whom it may concern:

Be itknown that I, LEWIS L. FosTER, a citizen of the United States, residing at Govans, in the county of Baltimore and State of Maryland, have invented certain new and useful Improvements in Air-Compressors, of which the following is a specification.

This invention relates to an improved air compressor and has as its primary object to provide a device of this character wherein each charge of air drawn in will be ini tially compressed and then subsequently recompressed before being discharged by the device.

The invention has as a further object to provide a compressor employing primary compression chambers forinitially compress ing the air as it is drawn into the device and also ennploying secondary compression chambers for then subsequently compressing the air and discharging the compressed air from the device.

A still further object of the invention is to provide a compressor wherein a single sleeve valve will be employed to control the intake and discharge of air into and'from both the primary and secondary c0mpression chambers.

And the invention has a further object to provide a compressor of the above described character which will be double acting so that acharge of'compressed air will be discharged from the device at each stroke of the piston employed.

Other and incidental objects will appear as the description proceeds and in the drawings wherein I have illustrated the preferred embodiment of the invention and wherein similarreference characters designate corresponding parts throughout the several views: Q i

Figure 1 is a vertical'sectional view of my improved compressor'showing the piston of the device at the 5 top of its stroke,

Fig. 2 is a similar view showing the piston at the bottom of its stroke,

Fig.3 is a vertical sectional view showing the connectionsbetween the piston and thedrive shaft of the'device,

4 is a transverse sectional view taken line HOf Fig. 2 and looking in the direetionof the arrows,1th-1s view par- Fig.

"ti culafrly illustrating the spider employed for supporting the inner cylinder of the compressor,

' Fig. 5 is a transverse sectional View taken on the line 5-5 of Fig. 2 and looking in the direction of the arrows, this view showing the exhaust port for the upper secondary compression chamber of the device, and

Fig. 6 is a transverse sectional view taken on the line 6-6 of Fig. 2 and looking in the direction of the arrows, this viewparticularly showing the intake port for the upper secondary compression chamber.

standing outer cylinder 14: formed at its lower end with an annular flange 15 to which is connected a closure plate 16 secured to the said flange by bolts or other suitable fastening devices which also act to' connect the cylinder with the crank ease. Projecting from the plate into the crank case is an arm or web 17 formed at its lower end with a journal receiving the crank shaft 11. Arranged concentrically within the upper extremity of the cylinder 1 1 is an inner cylinder 18 closed at its lower end by a removable cap 19. Screw threaded into the -upper extremity of the said cylinder is a hollow packing plug 20 formed with an axialsleeve 21terminating at its upper extremity in an extension 22. Screw threaded upon this extension is a spider 23 having,

- as particularly shown in Fig. 4 of the drawings, a plurality of radial arms 24:. These arms overhang the upper end of the cylinder 1 1 and seat upon anannular flange 25 carried by the adjacent terminal of the said cylinder. Connecting the said arms with thefiange are bolts or other suitable fastening devices 26. The spider 23 will thus rigidly support the cylinder 18 within the cylinder 14 and locking the spider upon the plug 20, area plurality of belts or other suitable fastening devices Slida-bly fitted between the inner and outer cylinders l l and 18 is a sleeve valve 28 closed at its lower end by a removable cap 29. This valve is, at its upper extremity, formed with a pluralityof longitudinally extending slots 30 to slidably receive the arms 24 of the spider 23 which therefore acts -to lock the sleeve valve against rotation, and screw threaded into the upper extremity of the said valve is a head 31. This head is formed upon its inner side with an axial boss 32' and screw threadedinto this boss is the rod 33 of a piston 3st mounted to reciprocate Within the cylinder 18 and having the rod 33 thereof slidably received through the sleeve 21 of the packing plug 20. The piston rod 33 is equipped with suitable packing rings 35 to bear Within the said sleeve, while the piston 34 is equipp'edw-ith similar rings 36. Also, the cylinder 18 and sleeve valve 28 are equipped with suitable packing rings 37, as may be found necessary.

Arranged upon the head 31 of the sleeve valve 28 are spaced bearings 38 through which is journaled a cross pin 39. Swingingly mounted upon the extremities of this pin are connecting rods 40 which project through suitable openings 41 in the crank case 10 and, at their lower ends, are secured to the cranks 12 of the crank shaft 11. Consequently, rotation of the'belt wheel 18 to drive the shaft 11 will simultaneously reciprocate the sleeve valve 28 and piston 34. At opposite sides of the openings 41, the crank case is formed with under-cut flanges 42 and slidably mounted. between the said flanges are closure plates 43 for the said openings. These plates loosely receive the connecting rods 4:0 to move therewith and will prevent the splashing of oil from the crank case 10 through the openings As will now behest observed upon reference to Fig. 1- 0f the drawings, a primary compression chamber 44 is provided within the cylinder ll below the lower end of the sleeve valve 28. A second primary compression chamber 15 is provided within the said sleeve valve below the lowercnd of the cylinder 18. *TflO'l'GOVCT, a secondary compression chamber l6 is provided within the cylinder 18 above the piston B lwhile a second sec "ondai'y' compression chamber 47 is provided within the said cylinder below the piston. "Formed through the lower extremity of the cylinder 14 at one side thereof is an intake port 48' in whic'h is mounted a: screened fitting l9. Leading tl'irough "the oppositesld'e of ;said cylinder from the-lower end of the compression chamber 44f is a passage 50 which enters throughthe cylinder 18 and forms, as shall presently appear, an intake passage for'th'e secondary compression chamber 46.

The sleeve valve 28, at its lower extremity, is provided upon one side thereof 'iwithi an intern at passage adapted. to be: brought into register with a port 52 leading into the lower secondary compression chamber 47. The port 52 opens through the cylinder ll to also provide, as shall presently appear, an exhaust port for the chamber 47. Entering through the cylinders 14 and 18 at a point above the port 52, is an exhaust port communicating with the upper secondary compression chamber l6. Fitted in the outer ends of the said exhaust ports and screw threaded upon the cylinder ll is a manifold 5l from which leads a compressed air pipe 55. The port l8 is arranged out of alincment with the ports and Fcrmed through the lower extremity oi the sleeve valve 28, upon one side thereof, is an intake port 57 adapted to register with the intake por't'lS. This valve is further provided with vertically spaced exhaust ports 58 and 59. The ports 58 and 59 are arranged in the same vertical plane with the ports and Formed through the sleeve valve at the side thereof opposite the exhaust ports of the said valve, is an intake port 60.

It will now be assumed that the drive wheel 1.3 has been rotated to shift the piston 34. upwardly trom the position shown in Fig. 2 of the drawings, to the top of its stroke, as illustrated in Fig. Upward movement of the sleeve valve 28 with the piston will create a partial vacuum withinthe lower primary compression chamber l4: so that as soon as the lower end of the said valve passes over the intakcport 48, a charge of air will be drawn into the said chamber. Downward n rovenient of the piston Bl from the position shown in Fig. 1, to the bottoin off its stroke, as shown in Fig. 2, will then --cause the valve to initially compress the charge of air within the chamber ll, and at the same time create a partial vacuum within the primary compression chamber 45..

When the piston has reached the bottom of its stroke, the intake port 57 will be brought into register with the port 48 so that a charge of air will then be drawn into the said. chamber 45; At the same time, the intake port 60 of the valve will be'brought into register with the passage 50 sothat the compressed charge or air within the pa mary compress-ion chamber l ltwill forcedby the said valve through the said passage and into the upper secondary compression chamber 46. lhepiston, upon again: moving upwardly. will therefore ttgitllLfOHlP'lfGSS the charge of air within theieha'mber 46 received tron'r 'the'cha'inber ll while, at thesame time, the valve 28 will initially compress the charge otair-draw-n into the secondary co1npreslon chamber VVhemthepiston has reached the top of its stroke, the discharge:

passage 58 of the valve'wi ll 'benbrought into register with the discharge port253, when the doublyicompressed-charge of air Within the iippenseco'ntlai y vVcompression chamber 16 will be forced by the piston out through the pipe At the same time, the passage 51 of the valve will, as shown in Fig. 1, be brought into register with the inner portion of the passage 52 so that the compressed charge of air within the primary compression chamber 45 will be forced into the lower secondary compression chamber a7. 'Therefore, the piston, upon again moving downwardly, will again compress this charge of air within. the chamber 47 while the valve 28 will as previously described, initially compress a charge of air within the chamber let. When the piston has again reached the bottom of its stroke, the discharge port 59 of the valve will be brought into register with the discharge port 5:2 so that the doubly compressed charge of air within the secondary compression chamber a7 will -be forced by the piston out through the pipe At the same time, the compressed charge of air within the chamber 44 will, as previously described, be admitted to the upper secondary compression chamber 46.

It will therefore be. seen that the device will thus continuously operate to draw in, each time the piston moves upwardly, a charge of air within the primary compression chamber it, to initially compress a charge of air within the primary compression chamber 45 and to recompress a charge of air within the upper secondary compression chamber 46. In like manner, each time the piston moves downwardly, a charge of ir will be initially compressed within the chamber 4A, a charge of air will be drawn into thechamber 4:5, and a charge of air will be recompressed within the chamber 4&7. Each charge of-air drawn in by the device will thus be initially compressed and will then again be subsequently recompresscd while at the same time, a charge of air will be discharged from the device at each stroke of the piston to thus render the compressor double acting, Furthermore, it will be noted that the intake and exhaust of air into and from both the primary compression chambers and the secondary compression chamhers is controlled by a singlesleeve valve which also cooperates with the cylinders of the device to itself provide a piston for initiall y compressing the air drawn into the device. For heavy duty, the pump may be either air cooled or water cooled and since such cooling may be eflect-ed in any approved manner, 1 cooling system for the pump has not been shown.

Having thus described the invention, what is claimed as newis:

1. An air compressor including inner and outer cylinders, a sleeve valve slidably mounted between thesaid cylinders and coacting therewith to provide primary compression chambe s, a piston mount to re ciprocate within'the inner cylinder, the said inner cylinder providing secondary compression chambers at opposite sides of said piston, an intake port for the primary compression chambers, passages for establishing communication between the primary and secondary compression chambers, and exhaust ports for the said secondary compression chambers, the sleeve valve being movable for opening and closing said passages and the said ports.

2. An air compressor including inner and outer cylinders. a sleeve valve mounted to slide between the said cylinders and coact ing therewith to provide primary compression chambers, a piston mounted to reciprocate within the inner cylinder, passages for establishing communication between the said chambers and the inner cylinder at opposite sides of the said piston, an intake port for the said chambers and exhaust oorts leadin from the inner cylind r at opposite sides of 7 being movable the piston, the sleeve valve passages and for opening and closing said the said ports.

c 3. An air compressor includingiuner and outer cylinders, a sleeve valve mounted to slide between the said cylinders and coacting therewith to provide primary compression chambers, a piston mounted to reciprocate within the inner cylinder, passages for establishing communication between the said chambers and the inner cylinder at opposite sides of the said piston, an intake port for the said chambers, and exhaust ports rcading from the inner cylinder at opposite sides of the piston, the sleeve valve being movable with the piston for compressing a charge of air within one of said' chambers and drawing in a charge of air within the other of said chan'ibers and controlling communication between the chambers and the inner cylinder through said passages for adinitt-ing the CODUQJW-SGil charge of air at one cation between each of the said primary compression chambers and one of the secondary compression chambers, an intake port for the primary compression chambers, and exhaust ports for the secondary compression chambers, the sleeve valve being movable for opening and closing said passages and the said ports'for drawing in a charge of air into one of the primary compression chambers, for compressing a charge of air Within the other of the primary compression chambers and forcing the said compressed charge into one of the secondary compression chambers and opening the exhaust port of the other of the secondary compression chambers at each stroke of the piston.

5. An air compressor including inner and outer cylinders, a piston mounted to reciprocate within the inner cylinder, exhaust ports leading from the said inner cylinder at opposite sides of the piston, a sleeve valve mounted to slide between the cylinders and coacting therewith to provide compression chambers, an intake port for the said chambers, and passages for establishing communication between the chambers and the inner cylinder at opposite sides of the said piston, the sleeve valve being movable with the piston for opening and closing said passages and the said ports and for initially compressing a charge of air within one of the said chambers at one side of the piston at each stroke thereof to be subsequently recompressed by the piston upon its next stroke.

6. An air compressor including inner and outer cylinders, a piston mounted to reciprocate within the inner cylinder, a sleeve valve mounted to slide between the cylinders and coacting therewith to provide compression chambers, exhaust ports leading from the inner cylinder at opposite sides of the piston, an intake port for the said chambers, and passages for establishing communication between the chambers and the inner cylinder at opposite sides of the piston, the valve being movable with the piston for opening and closing said ports to permit the discharge of a compressed charge of air from the inner cylinder at each stroke of the piston and to introduce a compressed charge of air from one of the said chambers into the inner cylinder at one side of the piston.

7. An air compressor including inner and outer cylinders, a piston mounted to reciprocate within the inner cylinder, exhaust ports leading from the inner cylinder at opposite sides of the piston, a sleeve valve mounted to slide between the said cylinders v and movable with the cylinders for opening one of said ports and closing the other at each stroke of the piston, said valve cooperating with the said cylinders to provide compression chambers, an intake port for the said chambers, and passages for estab lishing communication between the said chambers and the inner cylinder at opposite sides of the piston, the sleeve valve being also movable with the piston for drawing in a charge of air into one of said chambers, for compressing a charge within the other of said chambers, and for establishing communication between the said last mentioned chamber and the inner cylinder at one side of the piston at each stroke thereof.

8. An air compressor including inner and outer cylinders, a packing plug closing the inner cylinder, a piston mounted to reciprocate within the inner cylinder and having the rod thereof slidably received through said plug means carried by the piston rod and cooperating with the plug to provide a tight joint between the piston rod and the plug, a sleeve valve connected with the piston and slidably mounted between the said cylinders, the said sleeve valve coacting with the cylinders to provide primary compression chambers and the inner cylinder providing secondary compression chambers at opposite sides of said piston, an intake port for the primary compression chambers, passages for establishing communication between the primary and secondary compression chambers, and exhaust ports for the said secondary compression chambers, the sleeve valve being movable with the piston for opening and closing said passages and the said ports.

In testimony whereof I aflix my signature.

LEWIS L. FOSTER; [1,. s]

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